Construction of novel polybenzoxazine coating precursor exhibiting excellent anti-corrosion performance through monomer design

Abstract

In this study, we utilized salicylaldehyde (SA) and p-toluidine (Tol-NH2) to synthesize 2-(Z)[(4-methylphenyl)imino]methylphenol (SA-Tol-SF), which was then reduced to 2-[(4-methylphenyl)amino]methylphenol, producing SA-Tol-NH. SA-Tol-NH was further reacted with formaldehyde to create SA-Tol-BZ monomer. Poly(SA-Tol-BZ) was produced by thermally curing it at 210 °C, after synthesizing it from SA-Tol-BZ. The chemical structure of SA-Tol-BZ was analyzed using various analytical techniques such as FT-IR, 1H NMR spectroscopy, and 13C NMR spectroscopy TGA, SEM, DSC, and X-ray analyses. Afterward, we applied the obtained poly(SA-Tol-BZ) onto mild steel (MS) using thermal curing and spray coating techniques. To examine the anticorrosion attributes of MS coated with poly(SA-Tol-BZ), electrochemical characterization was employed. The study proved that poly(SA-Tol-BZ) coating had a high level of effectiveness in preventing corrosion on MS, with an efficacy of 96.52%, and also exhibited hydrophobic properties.